Add expansion of shorthands with custom properties to longhands using a pending substition value.

third_party/WebKit/Source/core/css/resolver/CSSVariableResolver.h

Index: third_party/WebKit/Source/core/css/resolver/CSSVariableResolver.h
diff --git a/third_party/WebKit/Source/core/css/resolver/CSSVariableResolver.h b/third_party/WebKit/Source/core/css/resolver/CSSVariableResolver.h
index c1150ff78c650a1d38e2993b4207ff1ef9e6a59a..e58d7fb3e53f529e21f6da885fd1b3392ae35d03 100644
--- a/third_party/WebKit/Source/core/css/resolver/CSSVariableResolver.h
+++ b/third_party/WebKit/Source/core/css/resolver/CSSVariableResolver.h
@@ -14,6 +14,7 @@
 namespace blink {
 
 class CSSParserTokenRange;
+class CSSPendingSubstitutionValue;
 class CSSVariableData;
 class CSSVariableReferenceValue;
 class StyleResolverState;
@@ -22,7 +23,8 @@ class StyleVariableData;
 class CSSVariableResolver {
 public:
     static void resolveVariableDefinitions(StyleVariableData*);
-    static void resolveAndApplyVariableReferences(StyleResolverState&, CSSPropertyID, const CSSVariableReferenceValue&);
+    const static CSSValue* resolveVariableReferences(StyleResolverState&, CSSPropertyID, const CSSVariableReferenceValue&);

[Timothy Loh, 2016/06/22 00:06:12]

static const

[Andy Mutton, 2016/06/24 04:53:26]

Done.

+    const static CSSValue* resolvePendingSubstitutions(StyleResolverState&, CSSPropertyID, const CSSPendingSubstitutionValue&);
 
     // Shorthand properties are not supported.
     static CSSValue* resolveVariableReferences(StyleVariableData*, CSSPropertyID, const CSSVariableReferenceValue&);